Manufacture of urea.



NERESHEIMER, CARL BOSCH, AND MITTASCH, OF LUDWIGSHAFEN-ON- THE-RHIN'E, GERMANY, ASSIGNORS TO BADISCHE ANILIN & SODA FABRIK, OF LUDWIGSHAFEN-ON-THE-RHINE, GERMANY, A (IORPOIIEtA'lITION'v OF GERMANY.

MANUFACTURE OF UREA.

Specification of Letters Patent.

Patented J an. 21, 1919.

No Drawing; Original application filed April 16,- 1915, Serial No. 21,911. Divided and this application filed .December 20, 1918. Serial No. 188,122.

To all whom it may concern Be it known that we, KARL NERESHEIMER, CARL Boson, and ALwIN MITTAsoH, citizens of the German Empire, residing at Ludwigshafen-on-the-Rhine, Germany, have inbaminate with an addition of a catalyzer.

The present application is a division of application Serial No. 21,911 filed April 16. 1915. In the present application, we wish to claim the employment of salts of light metals as catalyzers, which has been described in the said original application, but

now is not claimed specifically therein. As

we found, salts of light metals, within which term we include also the-ammonium salts, possess, even when employed in small quantities', the property of accelerating the formation of urea. For instance, carbonates, nitrates, sulfates, sulfids, chloride of the alkali metalsincluding ammonium-and of the alkaline earth'metals can be used, but the use of the ammonium salts of carbonic acid-by which only water in a loosely combined state is introduced into the process is not claimed in the present invention, this being included in the said original application. More than one of such salts can be used simultaneously, if desired, and at the same time a small quantity of water or of ammonium carbonate can be added which also will act catalytically, according to our co ending application Serial Number21911.

e following examples serve to illustrate the invention .but the invention is not confined to the examples.

Eaiwmqale 1.

Mix ammonium carbaminate with 5% of potassium carbonate, grinding the bodies togather. Heat the mixture in a vessel capable of withstanding pressure at atemperature with ammonium carbaminate alone.

of 135 to 140 degrees C. The formation of urea takes place much more quickly than stead of potassium carbonate the following can be used, sodium sulfate, sodium sulfid, sodium formate, calcium chlorid, and many others. These can be added in the dry state or in aqueous solution. If desired the catalyst can be removed from the end product, foi-1 ilnstance by dissolving the urea in alco 0 Ewa/mple Mix together ammonium carbaminate and 3% of its weight of ammonium sulfite and heat the mixture as described in the previous gether with the unaltered ammonium oarbaminate, the ammonium carbonate and the water formed are removed by distillation. Ammonium salts of other acids can be employed in the same way, onfree acids themselves may be added, forming at once the respective ammonium salts by decomposing some ammonium carbamate. As instances of suitable amonium salts we mention the selenite, chlorid, acetate, oxalate, and citrate.

Now what we claim is 1. The manufacture of urea by heating ammonium carbaminate with an addition of a salt of a light metal.

2. The manufacture of urea by heating example. From the product the catalyst toammonium carbaminate with an addition of an ammonium salt of an acid other than carbonic acid.

3. The manufacture of urea by heating ammonium carbaminate with an addition of a salt of a light metal and water in are stricted quantity leaving at least half of the ammonium carbaminate unaltered.

. Intestimony whereof we have hereunto set our hands in the presence of two subscribing witnesses.

Y KARL NERESHEIMER.

CARL BOSCH. .ALWIN MITTASOH. Witnesses as to Karl Nercsheimer Hnmmon ASGHZENBRANDT, Wnmir Mussnn. 

